Obstruction of urine flow by gravid uterus or dilated ovarian plexuses
--> Progressive dilatation of the renal pelvis, calyces, and ureters from the 2nd or 3rd months of pregnancy
GFR and RPF increase by 50% during 1st trimester
* Due to increased cardiac output
* Urea and creatinine falls in the first 2 trimesters
Glycosuria is common
Due to
Proteinuria is present in 20%
May be due to increased renal venous pressure